One field for this invention is directed to a weed and grass cutting machine which effects the cutting action by means of a length of a flexible band or bands, and more particularly to a portable power driven device which is capable of being readily moved by a person to achieve the cutting action.
In the past, there have been devices which employ a flexible line to achieve cutting weeds and grasses. These flexible line devices have been known to take the form of a power source attached to a shaft which, in turn, is connected to a whirling or rotating line holding head or housing. Within the head or housing is at least one flexible cord that extends exteriorly of the housing. The head or housing is rotated at a speed sufficient to create line rigidity. The whirling cord is to be employed to cut grass, weeds, and edge lawns. If the cord breaks, an additional length of cord is unwound. Besides the advantage of such devices being useable in relatively inaccessible areas, such devices also have the advantage that if the cord comes into contact with the operator's leg, hand or arm, the whirling cord would, at most, cause only a small welt upon the operator's skin. Therefore, by using such devices, there is a significantly greater degree of safety than was previously possible with rigid steel blade types of cutting devices.
One disadvantage of the prior art type of cord cutting devices is that the cord has been known to be readily breakable. Once a cord was broken, it was necessary to stop the device, extract an additional length of cord and cut the cords to equal length to retain satisfactory dynamic balance prior to operating the device. It has not been uncommon to have many cords break in a short time under heavy cutting conditions. This means that there has been a significant amount of "down" time which is most time consuming. This stop-start operation increases power source wear and energy usage.
There is a definite need for a line cutting apparatus in which the line member is of a substantially superior strength to the line members incorporated in prior line cutting apparatuses. In the event the line member does break, a cutting device may be automatically activated to sever all line members and then appropriate line extending means provided to extend new portions of line members with each line member being of equal length. This extending of the line member and the cutting of the old line members is to be accomplished quickly and easily and in a matter of seconds without power shutdown. There is a further need for quick and easy replacement of the spool incorporated within the device upon which the line members are wound preferably without the use of hand tools.